Method of retaining and sealing furnace structure



July 28, 1931. R. 1.. FRINK 1,816,322

METHOD OF RE'lAIIIINGr AND SEALING FURNACE STRUCTURES Filed Dec. 16 192Patented Jul 28, ,1931

' RoBERrL. ERIN or LANCASTER, oHIo METHOD or RETAINI' GT AND SEALINGFURNACE s'rnuo'runr Application filed DecemberIG, 19 26. Serial No."155,329.

1 This invention relates to methodof retaining and sealing liningsresistant to erosion Where thereis more or less' chemical action andheat, and in its more specificaspects, it

f5, has reference to linings for furnaces treating materials inindustrial usages such as involve severe action along heated zonesofcontact. For example,in glass melting tanks, thelinings are subjectedtovery drastic conditions.

I Likewise-with copper refining furnaces, also boilerfurnaces,'particularly those fired by powdered coal, 6130;, where theerosion'is very severe. .Very durabIe or highly refractory materialsare' knownthat offer advantages but their high cost has rendered theiruse prohibitive in the dimensions required in the prevalentself-supporting types of construction. Moreover,;with such refractorymaterials'as mullite, etc., the heat-"conductivity is such that thesematerials if used alone would permit excessive'iheat losses through thewalls. In accordance with my present invention, it now becomes possibleto secure a highly-resistant surface together with the other-qualities,desirable at the same time, and coincidentally produce a-sealing ofthe 1joints.

" Tothe accomplishment :of the foregoing and related ends, theinvention, then, consists in'ithe features hereinafter fully describedand particularly pointed out in the claims, the following. descriptionand the annexed drawings illustrating buta few of the variousforms inwhich the principle of the' inven-. tion may be used.

*In said annexed drawings Fig. 1' is a fragmentary isometric and sectionalview. showing aportion of a wall and floor construction embodyingthe present invention; Fig. 2 is'a similar view of a modifi-' cation;and Fig. '3 is a sectional view illustrating the invention as applied toeffect a seal betweenjointsqv -The reference numerals 1 and 2inthedrawings yjdesignate facing slabs, or "blocks of highly-resistantordurable material. This may be selectedas desirablefor a' particue larusage in vi'ew. For example, with a glass melting furnace, or: tank.mulliteor sillima nite, maybe employed. Back of the facing naces, Iprefer to make up amixture of disslabs aresupport or backing blocks 3,4, of

inferior material and which maybe of'less density. Blocks 5v and 6 ofordinaryfireclay material form the base, and ablock 7 of sim ilarmaterial may-be arrangedabove. By y. providing the blocks (Sand 7 withunder-cuts or rebates or the like, asfor instance at 8, andcorrespondingly shaping the coacting edges of thelfacings land 2, thelatter'will be restrained against displacement 'forso Wardly and atthesame time they are held against the backing 3 and 4. 'As a furthersafeguard, there may be provided a sort of dovetailing of more orlesspronounced form,

as at 10in themating edges of the facing 66' slabs so as to' assist inretainingthese in relation; In assembling the construction as shownin-Fig-l. the'fioor or base blocks 5,, 6, are laidin position and thenthe backing blocks 3,4. ,Thefacingslabs land Qare 7e nowiset in positionandthen the top block 7 which with its overhanging edge serves tomaintain thefacing in position;

In some instances, I not-only secure the respective'members togetherbutv also efi'ect a seal by providing in the mating surfaces grooveswhich may be of circular orsquare cross section for instance asat 11 or12 or of double under-cut cross section as at 2. Such grooves, with therespective blocks. assembled, present then longitudinal'channelsinvolvingboth mating surfaces, and these channels arethenfilled'with a locking key which may bezof square section asat.13,whichispreferable for certain. kinds of seals. Preferably and -.mostconveniently, such .a key may be provided by. forcing in a plastic masswhich when properly set will afford a suitable mechanical tie. As to thecharacteristics of such mass, it is desirable ofcourse that it becapable offresisting temperatures to which thewall'structure may besubjected in use, and accordingly the particular ma; terial mayfva'ry as'determined'by the usage iniview. It is desirable alsoin most cases at'05 least that the key, masshavea coefficient of expansion andcontraction practicably re late'dto' that of the blockstiedtogether orseal to be made. :In the case ofv glass furintegrated sillinianite witha binder comprising silica, boric acid, thorium or zireoninin oxide,magnesium oxide and magnesium chloride, the respective quantities ofeach of the constituents being determined by the use to which it is tobe applied, i. e., the relative co-efficient of expansion between theparts to be joined, or the conditions under which a seal is to be madeand maintained; in each case, the quantity of magnesium on ide andmagnesium chloride to be used will depend upon the amount of cementingaction desired. Just enough water is added to dampen the mass and makeitadequately flowable to be inserted into the channels, and these havingbeen filled from a convenient oint of access, usually at the end, themass is allowed to dry out, and is ultimately set to final condition byheat, the temperature heingsuch that incipient fusion or softening toan: extent of allowing the adherence of the particles occurs. VVhereakey effect only is desired,themass should be brought toa temperatureabove 1400 C. unless the posi tion in: which the key is 'zised and thetemperature towhich it is subjected is a mere nominal'temperature offrom 1200 to 1300 Q, Where it would then be feasible to use a mixtnrehaving arlower melting point, as by the addition of alkali boratesor carbonates. It is. advisable that the softening temperature bemaintained somewhat longer in order to aillowof chemical and physicaladjustments in the mass. It will then be found that the plastic materialhas become a rigid key whose fusion pointis so high that it mechanicallyholds in the conditions of usage to which the furnace is thereaftersubjected. The firing temperature for the setting of the plastickeymixture will of course vary with the parti-cular material employed,but where such material is substantially of a sillimanite and boronsilicate type instanced above, a temperature of 1400 to 1500 C. or morewill be desirable.

As shownin Fig. 3, Inembersmay be joined with w seal to form hollowbodies or conduits, 815 for a recuperator system.

It has been found that to construct a recu perator tile by any of thepresent known methods, thatproduce the same in an integral piece, isunsatisfactory because ofthe variation of temperatures that occur, andthe" continued subjection of high tempera tures over long periods oftime causes such tiles to crack, especially where the partition member 9is subjected to a higher temperature than the walls" 9'. An unequal ordifferential expansion occurs between the walls 9 and'sec-tion 9 causingcracking and disinte "grationf It will be appreciated that, when thesetiles are used in recuperators eitherthe exterior is subjected. to atemperarture of atmowher'ie air while the. gases flowing through theinterior-may have a tempbrature of 1200 or 1300 C.., or the conditionsmay be vice versa.

To also meet these conditions and avoid such cracking of the tiles orconduits, with consequent leakage of the ingoing air and outgoing hotgases, thus necessitating the closing down of the furnace, my inventionis found entirely satisfactory when properly executed, and while theprinciple and the elements embodied are substantially the same whetherused as a seal or a key, when used as a seal I preferably employ thefollowing procedure:

Grooves are ground or formed into the mating surfaces between members 9and 9'. The parts are-brought into the required alignment and a mixtureof'sillimanite or mul lite wit-hboric acid, thoria orzirconium oxide iscompounded withmagnesium oxide and chloride, the mass is moistened andisthen injected bymeans of a pressure device or gun into'the recesses asshown in Fig. 3 un-: til'filled, as at 13. This is preferably doneduring the building of therecuperator or other furnace parts. lVhen heatis applied and the masses at 13 are sinteredror. fused, gases areevolved and some shrinkage takes place, and to govern the'quantity ofshrinkage required to compensate for differential movements betweenmembers 9 and 9, I may add varying quantities of alkali, carbonates, andraw fireclay which has been deflocculated or contains the largerpossible quantity of flocculant or colloidal. material.

Should itbe desired thatthe construction be more or less monolithic itis thenadvisa'ble to add increased quantities of alkali and carbonatesto" thereby lower the fusion point, creating a greater quantity ofglassy substance and obtain a relatively, larger surface of plasticmaterial in contact with the" mating surfaces.

It will thus be seen that with. a construction on the general linesdescribed, advantage may be taken .of the superior resistant propertiesof costly and difiicultly workable facing slabs in relatively thinsection, andlsuch lining may be'successfully backed up or used conjunction with cheaper and in some instances bet.- ter insulating substances,the assemblage being adequately held together in use by the overhangingengagement or by the plastically-introdu'ced key or both or' seal toclose pas sages that might allow circulation of gases, asinrrecu'perators, or fluids, as between the notch block and floater, orthe bonds between spouts and base walls, etc. as circumstances may makeadvisable, the wedge surfaces or retreating wedge surfaces of therespective members making an effective and durable in terlock. inengagement whether initially rigid orplastic. Theextent to which-thefacing will be applied will of course depend upon the particular usagein hand. In some cases, the entire side walls and the floor' beingcovered, and in other cases only the side wall will require the facing.In other cases yet, all of the side wall will not require facing butonly the zone at the upper part where the material being heated has itsgeneral range of exposed surface as a fluid level line con tacting theWall. v

Moreover, irrespective of the particular character of the membersto bejoined, whether in a solid wall or a hollow built-up structure, thewedging or locking member provides holding or sealing functions or both,and by the terms wedging member or locking member hereinafter, Icontemplate either or the invention may be employed, change being Itinctly claim as my invention made in the details set forth, providedthe means and steps stated in the following claims or the equivalent ofsuch be employed.

I therefore particularly point out and dis- 1. In construction of thecharacter described, the combination of heat-resistant members havingapposed surfaces provided with recesses, and a locking member fused insuch recesses the locking member being glass like in character.

2. In construction of the character described, the combination ofheat-resistant members having apposed surfaces provided with recesses,and alocking member of glasslike composition fused in such recesses.

3. In construction of the character described, the combination of afacing block resistant against action of material to be treated incontact therewith, a backing of less resistant material, and heatresistant locking members for holding sald facing against the backing.

4. In consiruction of the character de- K scribed, the combination of. afacing block substantially resistant against action of material to betreated in contact therewith, a backing of less resistant material, andheat resistant locking members comprising upper and lower blocks havingnon-planar surfaces for holding said facing against the backing.

5. In construction of the character described, the combination of arefractory facing block highly resistant against action of materials tobe treated in contact therewith, a backing of less resistant material,andfusible locking members engaging the facing and backing.

the character described, which comprises apposing heat-resistant membershaving mating channels, forcing a plastic locking material into suchchannels, and fusing at least a portion of the locking material.

10. A-method of making a construction of the character described, whichcomprises apposing a facing and a backing having mat-- ing channels,forcing a plastic material into such channels, and suIo ecting thematerial to heat to set the same mto required rigid form.

11. A method of making a construction of.

the character described, which comprises setting up a backing apposing arefractory facing thereagainst, said backing and facing having matingchannels'so formed as to coact with material therein to key the backingand the facing together, forcing into the channels a plastic materialcapable of setting when heated, and heatin 1.2. In a wall madeup of aplurality of apposed members, the combination with recesses in adjacentfaces of said members, of a keying and sealing member disposed in saidrecesses and fused to said members.

Signed by me this 14th day of December,

ROBERT L. FRINK.

